Effect of calcium on acute toxicity of aluminum in juvenile rainbow trout (Oncorhynchus mykiss) exposed to different pH waters

Rolando Vega, José Zamorano, Francisco Encina, Alfonso Mardones


DOI: https://doi.org/10.3856/vol43-issue2-fulltext-10

Important events of acute mortality without apparent pathological features are present in the salmon smolt production in the Araucanía Region (southern Chile). The problem is focused on specimens of 0.2 to 1 g; causes points to pH acidification processes of running water and the presence of certain heavy metals, among which aluminum, reaches concentrations beyond ranges tolerated by fish. Scientific information indicates that concentrations of 5 mg Ca L-1 in the affluent are enough to keep the fish safe from toxic effects of aluminum. However, problems in the production of smolt indicate that greater scientific knowledge and experimental evidence is required that supports the development of processes and technologies for effluent treatment in Chilean fish farms. In this work the effect of four calcium concentrations (0, 5, 10 and 20 mg Ca L-1) on the acute toxicity of 500 mg Al L-1 in juvenile rainbow trout (Oncorhynchus mykiss) of 0.1 g was evaluated in culture water at pH 5, 6 and 7. The objective was to determine the dose of calcium that reduces the acute toxicity of aluminum and the reaction times that fish farmers could have to take preventive measures for acute aluminum concentration in the culture water. The results indicate that within 8 h of exposure to a toxic concentration of aluminum farmers should ensure a dose exceeding 10 mg Ca L-1 in the culture water and pH >6 as remedial measure to reduce the effect of acute intoxication for aluminum.

Vega R, Zamorano J, Encina F, Mardones A. Effect of calcium on acute toxicity of aluminum in juvenile rainbow trout (Oncorhynchus mykiss) exposed to different pH waters. Lat. Am. J. Aquat. Res.. 2017;43(2): 337-343. Available from: doi:10.3856/vol43-issue2-fulltext-10 [Accessed 17 Oct. 2019].
Vega, R., Zamorano, J., Encina, F., & Mardones, A. (2017). Effect of calcium on acute toxicity of aluminum in juvenile rainbow trout (Oncorhynchus mykiss) exposed to different pH waters. Latin American Journal of Aquatic Research, 43(2), 337-343. doi:http://dx.doi.org/10.3856/vol43-issue2-fulltext-10